Mountain Flying

1
Mountain Flying

• How NOT to die

2
Mountain Flying
3
Mountain Flying

• Weather and Flight Planning
• Downdrafts Updrafts
• Turbulence, Rotors, Wind Shear
• Density Altitude
• Clearing Mountains
• Landing
• Ground Speed TAS vs. IAS

4
Mountain Flying

• Takeoff Distance
• Oxygen
• Forced Landings
• Course Reversal
• Emergency Gear
• Controlled Flight into Terrain (CFIT)

5
Weather and Flight Planning

• Mountain weather can change rapidly
• Check forecasts
• Contact Flight Watch (122.0) often
• Colder temps ? greater chance for icing
• Fly early morning or late afternoon for lightest
  winds.

6
Weather and Flight Planning

• VFR over high terrain may be impossible
• Even though your departure/destination airports
  are experiencing good weather.
• Colorado Pilots Association recommends at least
  15 Miles visibility.

7
Weather and Flight Planning

• Mountain flying is not a guaranteed go.
• Check the forecast, and then test the waters.
• If you like what you see initially, proceed
• If not, turn back.
• Don't become too attached to completing your
  flight.
• Dont go if the weather is doubtful.

8
Weather and Flight Planning

• If stopping at multiple airports, use multiple
  flight plans.
• In general, if youll be stopping at multiple
  airports on a flight, its a good idea to use
  multiple flight plans.
• If your plane goes down in between two airports,
  search crews will have a much better idea of
  where to look.
• If one leg takes a bit more or less time than
  planned, the clock is reset when you open your
  next flight plan.

9
Weather and Flight Planning

• Make sure you know the winds aloft and at your
  destination airports.
• Try to plan your route so you are flying on
  upwind side of valleys and canyons.
• Always know where the wind is coming from.

10
Weather and Flight Planning

• Rotors/wind shear are basically guaranteed at 20
  kts,
• Especially on the lee side of a peak/ridge.
• Use visualization to determine possible downdraft
  areas.
• Air behaves like water. Ask yourself, "What would
  water do if it were flowing like the winds aloft?

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Weather and Flight Planning
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Weather and Flight Planning
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Weather and Flight Planning
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Weather and Flight Planning
15
Weather and Flight Planning

• The venturi effect in mountain passes can
  increase wind velocity significantly.
• This can produce winds in passes that are much
  stronger than winds aloft.
• Expect wind to be much greater velocity over
  mountain passes than reported in areas a few
  miles away.

16
Weather and Flight Planning

• Winds aloft greater than 30 knots at cruise
  altitude usually means the novice pilot should
  delay or postpone the flight until more favorable
  conditions prevail.

17
Weather and Flight Planning

• When approaching a ridge
• Inbound fly at 45 degree angle when ¼ to ½ mile
  out
• Outbound fly straight out (90 angle)
• get away as quickly as possible
• Downdrafts can be smooth or rapid/jolting
• Monitor the VSI
• A typical downdraft will produce a 1000 to 1500
  fpm descent

18
Weather and Flight Planning

• If caught in a downdraft
• Apply max power, Lean (for best power)
• Do not pull up!
• Its very common for people to pull up and then
  stall or enter a spin.
• People will often pull up and try to increase
  rate of turn by adding rudder.
• This is a perfect recipe for entering a spin at
  high altitudes.

19
Weather and Flight Planning

• Fly away at VA
• This may increase rate of descent, but it will
  get you out of downdraft as quickly as possible.
• The further you are from a ridge, the less
  turbulence and downdrafts you will experience.

20
Weather and Flight Planning

• Downdrafts on lee side of mountain ? updrafts on
  windward
• If you get caught in a downdraft, look for an
  area where the wind may be rising.
• Find rising air and then perform shallow turns to
  remain in the updraft.
• It may be necessary to fly toward a windward
  slope or some distance downwind before the
  aircraft can establish a positive rate of climb.

21
Weather and Flight Planning

• Most accidents caused by downdrafts are due to
  the pilot's concern about altitude loss.
• Dont try to out-climb a downdraft.
• Instead, try to escape away from the ridge that
  is causing the downdraft.

22
Weather and Flight Planning

• If lift (updrafts/downdrafts) is not a factor,
  fly on the appropriate side of the valley so that
  your 180 exit turn can be made into the wind.

23
Weather and Flight Planning

• Establish 2000 to 3000' clearance over mountains
• Plan to cross mountains at least 2,000 feet above
  the highest point along the route.
• This altitude should be reached well in advance,
  as some terrain will rise faster than the
  aircraft climb rate.

24
Weather and Flight Planning

• Lenticular clouds extreme turbulence
• Mountain waves can extend for tens or hundreds of
  miles
• In heavy turbulence, fly an attitude and accept
  altitude loss
• Don't over-stress the airframe

25
Weather and Flight Planning

• Dont rely on cloud shadows for wind direction
• Expect the wind to be constantly changing in
  direction and velocity because of modification by
  mountain ridges and canyons.
• Dont fly the middle of a canyon.
• This places you in a poor position to make a
  turnaround and it subjects you to shear
  turbulence.
• Fly on the downwind side of canyons to catch
  updrafts.

26
Weather and Flight Planning

• If you need to make a tight turn slow down.
• Flying slower provides for a more reaction time
  and a tighter turning radius.

27
Weather and Flight Planning

• There are three important factors that affect air
  density altitude, temperature, and humidity.

28
Weather and Flight Planning

• Calculate density altitude before your flight.
• Density altitude is the altitude the airplane
  thinks it is at and performs in accordance with.
• High, hot, and humid conditions may raise the
  effective physical altitude of an airstrip to a
  performance altitude many thousands of feet
  higher than its actual elevation.
• Be familiar with the performance of your aircraft
  at altitude service ceiling, takeoff and
  landing distance, climb rate.
• The horsepower output of the engine is decreased
  because its fuel air mixture intake is reduced.
• Normally aspirated engines lose about 3 percent
  of their horsepower for each 1,000 feet above sea
  level.
• For a normally aspirated engine, the maximum
  power you can generate at 7500 is 75.
• The propeller develops less thrust because the
  blades are less efficient.
• The wings develop less lift because the less
  dense atmosphere exerts less force on the wings
  as airfoils. As a result, the takeoff distance
  is increased and the climb performance reduced.

29
Weather and Flight Planning

• Know the performance of your airplane
• VY decreases with altitude.
• As a rule of thumb, subtract 1kt for every 1,000
  feet of density altitude.
• VG decreases as weight decreases.
• As a rule of thumb, VG decreases 2kts for every
  10 under maximum gross weight.
• Weight and density altitude are the two most
  important factors when considering the
  appropriate airspeed to fly for best rate of
  climb or best glide.
• Learn to interpolate to figure the proper
  performance data before you need it.
• Don't use short field flap settings for high
  density altitude takeoffs (unless the field is
  truly short.)
• Short field flap settings offer a better angle,
  not rate of climb.
• At the typically long high-elevation airports
  flaps will be a hindrance to reaching VY more
  quickly.

30
Weather and Flight Planning

• A good way to compensate for lower power is to be
  light.
• As a rule of thumb, being 10 under maximum gross
  weight provides a 20 performance benefit over
  the POH numbers.

31
Clearing Mountains

• The visual aspects of mountain flying can be
  deceiving.
• but if you can see more and more of the terrain
  on the other side of the ridge you are
  approaching, you are higher than the ridge and
  can probably continue.
• Plan every ridge crossing as though an engine
  failure was imminent.

32
Clearing Mountains

• BASIC PREMISE 1
• Always remain in a position where you can turn
  toward lowering terrain.
• This axiom also encompasses the idea that you
  will not enter or fly in a canyon where there is
  not sufficient room to turn around. Another way
  of stating this truth is to have an escape route
  in mind and be in a position to exercise this
  option.
• Sparky Imeson The Mountain Flying Bible

33
Clearing Mountains

• BASIC PREMISE 2
• Do not fly beyond the point of no return.
• This is the position when flying upslope terrain
  where, if you reduce the throttle to idle and
  begin a normal glide, you will have sufficient
  altitude to turn around without impacting the
  terrain.
• As you near the ridge, when arriving at a
  position where the power can be reduced to idle
  and the airplane will glide to the top of the
  ridgeline, a commitment to cross the ridge can be
  made.
• At this position, the airplane is close enough to
  the ridgeline not to experience an unexpected
  downdraft of a nature that will cause a problem.
• If a downdraft is encountered, keep the power on,
  lower the nose to maintain airspeed and the
  airplane will clear the ridge.
• Sparky Imeson The Mountain Flying Bible

34
Clearing Mountains

• Realize that the actual horizon is near the base
  of the mountains.
• This mistake of using the summit of the peaks as
  the horizon will result in the aircraft being
  placed in an attitude of constant climb.
• This could inadvertently lead to stall from which
  a recovery may be impossible.

35
Landing

• Landing at a short mountain strip requires exact
  airspeed control to eliminate float.
• A 10 increase in the proper approach speed
  results in a 21 increase in landing distance.

36
Landing

• Make sure to richen mixture for go-around
• Momentarily increase to full power when close to
  pattern altitude, but makes sure you have enough
  time to loose the airspeed youve gained.
• Richen to 50 100 rich of peak EGT.
• (50 is good for small engines, 100 good for
  high performance)
• Depending on your altitude, cruise power at high
  elevation is likely to also be maximum power.
• If this is the case, your fuel-air mixture is
  already properly set and requires no adjustment
  for landing.
• See your airplanes POH for the manufacturers
  recommended leaning procedures.

37
Landing

• "The most common problem for flatlanders is the
  tendency to fly the approach below the normal
  indicated airspeed for landing. Thus, an area of
  heavy emphasis for mountain flying is to fly by
  the numbers and approach to land at the normal
  indicated airspeed. -
  Colorado Pilots Association

38
Landing

• For safety from eddies, wind shear, and gusty
  conditions, plan your approach using the runway
  numbers as your aim point
• Flare 500 feet down the runway, and try to touch
  down on the 1,000 ft. marks.
• High altitude runways are quite long and this
  provides insurance in case of a severe downdraft.

39
Landing

• Be certain to use the same indicated airspeed at
  high-altitude airports that you use at
  low-altitude or sea level airports for the
  takeoff or for the approach to landing.
• When flying to remote airports, before landing,
  first overfly the field to check for wildlife and
  runway conditions.
• If you havent landed by ½-way down the runway,
  you should abort the landing.

40
Landing

• Runway Illusions
• Youll look high due to narrow runways
• Your eyes tend to focus on rising terrain/ridges.
• This will cause you to come in high if a hill is
  near the runway.

41
Landing

• Sloping runways are common in mountains
• This can create illusions of being too high
  (upside) or too low (downslope)
• The slope will also affect takeoff and landing
  distance.
• This can be a very significant important factor
  at mountain airports.

42
Ground Speed TAS vs. IAS

• Roughly, the TAS increases by 2 over IAS for
  every thousand feet altitude gain.
• This implies that at 10,000 the TAS will be
  about 20 higher (if calculated accurately its
  actually closer to 15)
• This is a built-in compensator for reduced lift
  caused by the thin air at higher altitude
  airports.
• Ground speed will be much higher, visual queues
  will be very different.
• Since TAS is higher, youll need to fly pattern
  wider than normal.

43
Takeoff Distance

• Before landing at a mountain airport, make sure
  you can climb back out.
• One technique you can use is to overfly the field
  at, say, 1500 feet AGL and apply full power.
• If you dont achieve at least 300fpm climb rate,
  you probably shouldnt land.
• A rule-of-thumb for operating from a short runway
  is that if you obtain 71 of the speed necessary
  for rotation at the ½-way point of the runway,
  you can take off in the remaining distance.
• Calculate this speed beforehand and review it as
  part of your pre-takeoff briefing.
• E.g. VR55kts - need to obtain 39kts at ½-way
  point.
• The ½-way point should be treated as a solid
  abort point.

44
Takeoff Distance

• Before takeoff, you must lean for max power
• For a plane with a direct drive engine and a
  fixed pitch propeller, before takeoff, hold the
  brakes, apply full throttle, lean to peak RPM (or
  50 100 rich of peak EGT).
• Leave mixture at that position and accomplish the
  takeoff.
• For a plane with a constant speed propeller,
  leaning is normally done using the EGT.
• See your POH for the manufacturers
  recommendation.

45
Takeoff Distance

• The takeoff distance varies with the gross
  weight.
• A 10 increase in gross weight will cause
• 5 increase in speed required for takeoff.
• 9 decrease in acceleration (from stop to takeoff
  speed).
• 21 increase in takeoff distance.
• You may not want full fuel on takeoff from a
  high-altitude airport.

46
Takeoff Distance

• A good "rule of thumb" for the pilot to remember
  is - for each thousand feet above sea level, the
  takeoff run increases approximately 25 percent.
• In the case of normally aspirated engines (not
  turbocharged or supercharged), at an altitude of
  10,000 feet, about one-half of available engine
  horsepower is lost.
• Example Denver, Colorado field elevation
  indicated on the altimeter is 5000 ft Summer day
  80F
• density altitude is 7500 feet
• the takeoff distance will be 2.3 times the sea
  level takeoff roll.
• The double whammy not only must the airplane be
  at a higher true airspeed to achieve flying
  speed, but it must do so with an engine that's
  not capable of making sea level horsepower.

47
Oxygen

• Density altitude can be much higher than
  indicated
• The effect of altitude on your body depends on
  the partial pressure of oxygen.
• Note that altimeters show pressure altitude
  (corrected for local altimeter setting).
• The U.S. Air Force recommends using oxygen
  starting at 8000ft.
• FAA regulations
• No O2 required until 12500 (although not
  required, it is recommended)
• Between 12500 and 14000, after ½ hour
• Higher than 14000, continuous
• Higher than 15000, must be provided for
  passengers

48
Oxygen

• Night vision is inhibited above 5000 pressure
  altitude.
• Cannulas can't be used above 18000'
• Manufacturers prohibit use above this altitude.
• Above this altitude, up to 25,000 you can use an
  oxygen mask.
• Regulator and flow meters fail, valves freeze,
  and lines plug up, so always be prepared to
  descend.
• It may make sense, because of the increased risk,
  to plan a flight at, say, 16,000 vs. 22,000.
• The time of useful consciousness at 20,000 is 30
  minutes
• At 22,000, the time of useful consciousness is
  about 10 minutes.
• Time of useful consciousness is sometimes also
  referred to as EPT, or Effective Performance Time.

49
Oxygen

• Oxygen bottles are normally low pressure
• 500 PSI, or high pressure
• 1800 PSI is the most common variety.
• The 1800 PSI bottles are green.
• Oxygen bottles need to be re-certified every 5
  years.

50
Oxygen

• It is a good idea to consider oxygen for flights
  above 5,000 feet at night and above 8,000 feet
  during the day.
• Use of pulse oximeter
• http//www.flightstat.nonin.com/Hypoxia.pdf
• http//www.radialsolutions.com/
• A general rule-of-thumb for using a pulse
  oximeter is to never let your oxygen saturation
  level get more than 10 percentage points below
  your home (ground level) saturation level.

51
Forced Landings

• Dont choose a route that would prevent a
  suitable forced-landing area
• In the event of a forced landing, approach at
  best glide, but touch down / impact at stall
  speed.
• Dont leave the airplane without a compelling
  reason if you have executed an emergency or
  precautionary landing.
• Temporary evacuation may be necessary if a fire
  hazard exists.

52
Forced Landings

• If you have a choice between landing in light
  green trees or dark green, head toward the light.
  
• Light green trees are more pliable, younger than
  dark green trees.
• Dont land in water.
• Youll flip upside down and, since the plane
  wont be visible, its less likely than youll be
  found.
• Also, mountain water is cold and you could
  contract hypothermia.

53
Forced Landings

• Follow roads whenever possible.
• Avoid flying over open water (Lake Tahoe, e.g.).
• Plan your trip along routes that include
  populated areas and well-known passes, or over
  valleys whenever possible.

54
Forced Landings

• Follow roads whenever possible.
• Avoid flying over open water (Lake Tahoe, e.g.).
• Plan your trip along routes that include
  populated areas and well-known passes, or over
  valleys whenever possible.
• Swaths cut through trees are usually power lines.
  Its usually best to avoid them.

55
Forced Landings

• ELT
• Learn how to turn it on.
• The ELT may not turn on automatically in a forced
  landing, so you may need to arm it manually.

56
Course Reversal

• Everyone flying in the mountains will encounter
  situations when it becomes necessary to make a
  180 turn.
• To turn around, slow down. This will decrease the
  radius of turn.
• Pull back on the control wheel to trade airspeed
  for altitude if you have extra speed.
• Then make the steepest turn you can comfortably
  make, up to 60 degrees.
• To execute a course reversal in IMC and end up
  over the same spot turn 90 followed by 270
• an 80 /260 also works

57
Emergency Gear

• Warm clothes
• Blankets or sleeping bags
• Food
• Water
• Flashlights
• Fire starter
• Radio
• Signaling mirror
• Maps
• Compass
• Wear or bring shoes you can use for hiking
• Always bring emergency gear when flying in the
  mountains.

58
Controlled Flight Into Terrain

• Controlled Flight into Terrain (CFIT) occurs when
  an airworthy aircraft under the control of a
  pilot is inadvertently flown into terrain, water,
  or an obstacle with inadequate awareness on the
  part of the pilot of the impending disaster.
• Cumulo-granite

59
Controlled Flight Into Terrain

• Accidents occur most frequently in GA operations
• 4.7 of all GA accidents and 32 of GA accidents
  in IMC.
• On average there are 1.4 fatalities per CFIT
  accident, versus 0.33 fatalities per GA accident
  overall.
• 17 of all GA fatalities are due to CFIT
• CFIT accidents are fatal 58 of the time.
• CFIT accidents occur 64 of the time in daytime
  and 36 at night
• 51 of CFIT accidents occur in IMC, 48 in VMC
  and 1 unknown.
• Impacted terrain was flat 45 and mountainous
  55.

60
Controlled Flight Into Terrain

• NTSB Identification DEN07FA05414 CFR Part 91
  General AviationAccident occurred Wednesday,
  January 17, 2007 in Centennial, WYAircraft
  Piper PA-28-180, registration N43630Injuries 3
  Fatal.
• This is preliminary information, subject to
  change, and may contain errors. Any errors in
  this report will be corrected when the final
  report has been completed.
• On January 17, 2007, approximately 2215 mountain
  standard time, a Piper PA-28-180, N43630,
  registered to Archer Nevada LLC, and piloted by a
  private pilot, was destroyed when it impacted
  mountainous terrain during cruise flight, 6 miles
  northwest of Centennial, Wyoming. Night visual
  meteorological conditions prevailed. The personal
  flight was being conducted under the provisions
  of Title 14 Code of Federal Regulations Part 91
  on a visual flight rules flight plan. The pilot
  and his two passengers were fatally injured. The
  cross-country flight departed the Rock
  Springs-Sweetwater County Airport (RKS)
  approximately 2115, and was en route to Grand
  Island, Nebraska (GRI).

61
Controlled Flight Into Terrain

• According to Blue Ridge Aeronautics, a flight
  school in Vacaville, California, the flight
  departed Nut Tree Airport (KVCB) approximately
  1100 Pacific standard time. The flight was to
  travel to Grand Island, Nebraska, on the 17th and
  continue on to Chicago, Illinois, on the 18th.
  The pilot reported to the flight school that he
  intended to follow Interstate 80 for the entire
  flight.According to the airport manager in RKS,
  the airplane arrived approximately 2030 and
  obtained fuel services. The airplane did not
  arrive in GRI and an Alert Notification (ALNOT)
  was issued for the missing airplane. According to
  National Track Analysis Program (NTAP), the
  airplane was tracked from RKS to 10 miles west of
  Centennial. Search and rescue crews located the
  airplane wreckage approximately 0830 on the
  morning of January 19th.

62
Controlled Flight Into Terrain

• The National Transportation Safety Board
  investigator-in-charge arrived on scene
  approximately 1300 on January 19, 2007. The
  accident site was located in mountainous,
  forested, snow covered terrain. A global
  positioning system receiver reported the
  coordinates of the main wreckage as 41 degrees 21
  minutes 58.6 seconds north latitude, and 106
  degrees 15 minutes 29.6 seconds west longitude.
  The accident site was at an elevation of 10,710
  feet mean sea level and the airplane impacted on
  a magnetic heading of 260 degrees. The wreckage
  consisted of the fuselage, empennage, and the
  left wing. The right wing separated partially and
  was found adjacent to the belly of the fuselage.
  The wreckage came to rest inverted in
  approximately 3 to 5 feet of snow.The closest
  official weather observation station was Laramie
  Regional Airport (KLAR), Laramie, Wyoming,
  located 27 nautical miles (nm) east of the
  accident site. The elevation of the weather
  observation station was 7,278 feet msl. The
  routine aviation weather report (METAR) for LAR,
  issued at 0953, reported, winds, 290 degrees at 9
  knots, gusting to 18 knots, visibility, 10
  statute miles sky condition, clear temperature
  minus 10 degrees Celsius (C) dewpoint, minus 18
  degrees C altimeter, 29.94 inches.

63
Controlled Flight Into Terrain
64
Further Study

• For Further Study
• http//www.mountainflying.com/
• Books by Sparky Imeson
• The Mountain Flying Bible
• The Shirt Pocket Mountain Flying Guide
• Order them here https//secure.airbase1.com/mtnf
  lying/orders.asp
• "Hypoxia, Oxygen and Pulse Oximetry," Furgang,
  Fred, MD.
• http//www.flightstat.nonin.com/Hypoxia.pdf
• Pulse Oximetry and the Oxyhemoglobin Dissociation
  Curve
• http//www.continuingeducation.com/nursing/pulseox
  /pulseox.pdf